#!/bin/bash

# -------------------------------------------------------------------------- #
# Copyright 2002-2016, OpenNebula Project, OpenNebula Systems                #
#                                                                            #
# Licensed under the Apache License, Version 2.0 (the "License"); you may    #
# not use this file except in compliance with the License. You may obtain    #
# a copy of the License at                                                   #
#                                                                            #
# http://www.apache.org/licenses/LICENSE-2.0                                 #
#                                                                            #
# Unless required by applicable law or agreed to in writing, software        #
# distributed under the License is distributed on an "AS IS" BASIS,          #
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   #
# See the License for the specific language governing permissions and        #
# limitations under the License.                                             #
#--------------------------------------------------------------------------- #

###############################################################################
# This script is used to monitor the free and used space of a datastore
###############################################################################

# -------- Set up the environment to source common tools & conf ------------

if [ -z "${ONE_LOCATION}" ]; then
    LIB_LOCATION=/usr/lib/one
else
    LIB_LOCATION=$ONE_LOCATION/lib
fi

. $LIB_LOCATION/sh/scripts_common.sh

DRIVER_PATH=$(dirname $0)
source ${DRIVER_PATH}/../libfs.sh

# -------- Get datastore arguments from OpenNebula core ------------

DRV_ACTION=$1
ID=$2

XPATH="${DRIVER_PATH}/../xpath.rb -b $DRV_ACTION"

unset i XPATH_ELEMENTS

while IFS= read -r -d '' element; do
    XPATH_ELEMENTS[i++]="$element"
done < <($XPATH     /DS_DRIVER_ACTION_DATA/DATASTORE/BASE_PATH \
                    /DS_DRIVER_ACTION_DATA/DATASTORE/TEMPLATE/BRIDGE_LIST)

unset i

BASE_PATH="${XPATH_ELEMENTS[i++]}"
BRIDGE_LIST="${XPATH_ELEMENTS[i++]}"

# ------------ Compute datastore usage -------------

MONITOR_SCRIPT=$(cat <<EOF
if [ ! -d $BASE_PATH ]; then
    mkdir -p $BASE_PATH
fi

USED_MB=\$(df -B1M -P $BASE_PATH 2>/dev/null | tail -n 1 | awk '{print \$3}')
TOTAL_MB=\$(df -B1M -P $BASE_PATH 2>/dev/null | tail -n 1 | awk '{print \$2}')
FREE_MB=\$(df -B1M -P $BASE_PATH 2>/dev/null | tail -n 1 | awk '{print \$4}')

if [ -z "\$USED_MB" -o -z "\$TOTAL_MB" -o -z "\$FREE_MB" ]; then
    msg="Empty value found"
    echo "\$msg: USED_MB=\$USED_MB, TOTAL_MB=\$TOTAL_MB, FREE_MB=\$FREE_MB"
    exit 1
fi

echo "USED_MB=\$USED_MB"
echo "FREE_MB=\$FREE_MB"
echo "TOTAL_MB=\$TOTAL_MB"
EOF
)

if [ -n "$BRIDGE_LIST" ]; then
    HOST=`get_destination_host`
    MONITOR_DATA=$(ssh_monitor_and_log "$HOST" "$MONITOR_SCRIPT" "Remote monitor script" 2>&1)
else
    MONITOR_DATA=$(monitor_and_log "$MONITOR_SCRIPT" "Monitor script" 2>&1)
fi

MONITOR_STATUS=$?

if [ "$MONITOR_STATUS" = "0" ]; then
    echo "$MONITOR_DATA" | tr ' ' '\n'
    exit 0
else
    echo "$MONITOR_DATA"
    exit $MONITOR_STATUS
fi
